A mixing container for mixing multiple materials is disclosed in, for example, Japanese Patent Publication No. 2002-104417 (JP 2002-104417) and Japanese Patent Publication No. 2001-136943 (JP 2001-136943) as containers that can be switched from a state in which two storage chambers are formed by a partition part to a state in which the two storage chambers are deformed into one storage chamber by deforming the partition part. According to these containers, the materials are stored in the respective storage chambers while the two storage chambers are formed, and a lid is subsequently put on to separately store the two materials. The lid is peeled before use, and the partition part is then deformed to put the storage chambers into one so that the two materials can be mixed.
A container disclosed in Japanese Unexamined Utility Model Application Publication No. 5-22374 (JP 5-22374) has a lid put on the container having two storage chambers with materials separately stored in the respective storage chambers such that when a pressing force is applied to one of the storage chambers, only a seal between the one storage chamber and the other storage chamber is peeled to allow the material in the one storage chamber to flow into the other storage chamber, so that the materials can be mixed while being covered with the lid.